The Ruins of Alph make a return in HeartGold & SoulSilver, however they feature a variety of changes which were included in Pokémon Crystal but not within Pokémon Gold & Silver. There are four chambers found within the Ruins of Alph each with a seperate puzzle to open access to the actual ruins

The Ruins

Once you do each puzzle and unlock access to the ruins, you can capture all 26 Unown (with more Unown becoming available with each puzzle completion). Two of the ruins access points are only accessible by going through Union Cave, so you cannot get all the Unown straight away.

The Ruins Extention

At the back of each chamber there is a little bit of Unown text which will give you a hint on what to do. If you follow the instructions, it accesses a new place in the ruins that holds 4 items and then another room with Unown text on the floor. The taskes are as follows

Upper Right Chamber: Use an Escape RopeLower Right Chamber: Use FlashUpper Left Chamber: Have Ho-Oh in the front of your partyLower Left Chamber: Have a Water Stone in your inventory

The ! & ? Unown

After you have captured all 26 Unown, another area is opened up in the main entrance to the ruins after talking to one of the researchers. This area contains only the ! and ? Unown and will allow you to complete your Unown Report dex and complete the Unown Sidequest itself

The Unown Report

In the house by the ruins, you can receive the Unown Report Key Item. This notebook details the details for every Unown that you have captured as well as research notes from each discovery you find including the extra extentions. Once you've discovered them, talk to the researcher once more. The first few pages deal with the Unown types

The research pages are as follows:

Page 4:
Mysterious stone plate puzzles have been found inside the ruins. Standing on that spot, the ground would suddenly cave in through a chamber underneath! It is almost as if these ancient ruins are trying to surprise us.The landing place was a huge room where rock statues were erected, and then the Unowns all of a sudden appeared. In other words, the stone plate puzzles have become the keys to awaken the Unowns from their sleep. These ruins are getting tougher and tougher.

Page 5:
We understand that using the Radio in the ruins will receive mysterious radio waves. This proves that the Unowns communicate with each other via radio waves.We understand that the Unowns have the same appearance as the different letters. Currently 26 kinds of letters have been identified, which means there are 26 kinds of Unowns as well. Have we seen them all?

Page 6:
We think that there is a lot of nonsense here, but the Unowns actually have an order. Things in the natural world may appear disorganized at a glance, but the truth is each of them follows a neat order.The staff of the research center has properly rearranged the disorganized records of the Unowns in the note according to their order. This makes understanding things about the Unown much easier.

Page 7:
Chambers which have Unown letters drawn on the ruins' grounds have been seen. What a big discovery! The people of the research center have gone in elation to investigate.There are more than 26 kinds of Unown writings. Two more letters have been discovered, which implies that somewhere lies two more kinds of Unowns.

Page 8:
We have copied the letters carved on the small chamber's stone plate into this note. "Companions bless our birth". We still don't know what this means.It seems necessary for the people of the research center to investigate the ruins once again, no...?

Page 9:
In the past, the Unowns and a tribe of humans lived in these ruins. To our understanding, it is said that the old Pokemon statues in the underground of the ruins were erected by this tribe. The Unowns were very timid and would not go outside the ruins. Since the ruins' surroundings are populated by more and more people, it is said that this tribe of people who wishes the Unown and humans to be able to live in harmony decided to leave here.